Impact of classroom exit design on evacuation efficiency of children in kindergarten under orderly evacuation scenarios

• Simulation modeling evaluates classroom exit design under teacher-led orderly evacuations in Chinese kindergartens. • Dual-exit strategies improve evacuation speed and queue stability across typical classroom layouts. • Exit positioning near dense furniture zones disrupts flow; spatial buffering is recommended. • Optimal dual-exit spacing patterns are identified under different layout conditions. • The findings support practical improvements to kindergarten exit planning and evacuation drills. This study examines teacher-guided, orderly evacuations in Chinese kindergartens. Using the MassMotion agent-based platform, two representative classroom prototypes (centralized and partitioned) were simulated under single- and dual-exit queuing strategies with multiple exit placements. Effects of exit configuration on evacuation efficiency were quantified, and the model was benchmarked against cumulative evacuee count–time curves from field drills. Results indicate that dual exits reduce total evacuation time in both layouts, with larger gains for the partitioned layout (approximately 12.4 %). Under orderly queuing, doorway widths within 1.2–1.8 m have no material effect on total evacuation time, whereas efficiency varies nonlinearly with dual-exit spacing, exhibiting an intermediate optimum at approximately 1.45 m (centralized) and 1.65 m (partitioned), which remained consistent across class sizes of N = 10 , 20 , and 30 . These findings provide context-specific guidance for exit strategy and spacing in kindergarten classrooms, with dual-exit schemes preferred where feasible.